Hand wrench

ABSTRACT

A hand wrench designed to clamp about a nut or bolt head of a specific size which may be tightly fastened to the nut or bolt in a difficult location. The wrench is fitted with a fixed jaw and a pivotable jaw, with the pivotable jaw fastened by linkage to a lever arm. Rotation of the lever arm tightens the jaw past the center axis of the linkage to result in a self-clamping grip of the jaws, about a specific size nut or bolt. A release bar serves to unlock the wrench by pushing the lever past the center axis of the linkage, when opening the jaws.

[451 Sept. 9, 1975 1 HAND WRENCH [75] Inventor: Jimmy R. Haight, Butler, Mo.

[73] Assignee: The Raymond Lee Organization,

Inc., New York, NY. a part interest [22] Filed: June 21, 1974 [21] Appl. No.: 481,649

[52] US. Cl. 81/111 [51] Int. Cl. B25B 13/40 [58] FieldofSearch ..8l/lll, 117

[56] References Cited UNITED STATES PATENTS 1,421,137 6/1922 Anderson et a1. 31/111 1,638,703 8/1927 Pcndleton 1. 81/111 X FOREIGN PATENTS OR APPLICATIONS 212,150 3/1924 United Kingdom 81/111 Primary Examiner-Al Lawrence Smith Assistant Examiner-James G. Smith Attorney, Agent, or FirmHoward I. Podell 5 7 ABSTRACT A hand wrench designed to clamp about a nut or bolt head of a specific size which may be tightly fastened to the nut or bolt in a difficult location. The wrench is fitted with a fixed jaw and a pivotable jaw, with the pivotable jaw fastened by linkage to a lever arm. Rotation of the lever arm tightens the jaw past the center axis of the linkage to result in a self-clamping grip of the jaws, about a specific size nut or bolt. A release bar serves to unlock the wrench by pushing the lever past the center axis of the linkage, when opening the aws.

1 Claim, 3 Drawing Figures HAND WRENCH SUMMARY OF THE INVENTION My invention relates to a hand wrench which may be tightly clamped about a specific size nut or bolt head. and particularly to a wrench with a fixed jaw and a pivotable jaw, with the pivotable jaw fastened by linkage to a lever arm.

Rotation of the lever arm of my wrench, in the closing direction, serves to move the adjustable jaw towards the fixed jaw. with the lever arm rotating past the center axis of the linkage and against a stop so as to tightly clamp a nut or bolt head of the proper size between the jaws. An auxiliary lever serves to open the jaws by rotating the lever arm past the dead center position of the linkage. in the opening direction.

BRIEF DESCRIPTION OF THE DRAWING The objects and features of the invention may be understood with reference to the following detailed de seription of an illustrative embodiment of the invention. taken together with the accompanying drawings in which:

FIG. 1 illustrates a plan view of the invention. with the wrench jaws in a closed position;

FIG. 2 illustrates a side view of the invention; and

FIG. 3 illustrates a plan veiw of the invention. with the jaws in an open position.

DESCRIPTION OF THE PREFERRED EMBODIMENT Turning now descriptively to the drawings. in which similar reference characters denote similar elements throughout the several views, FIGS. l-3 show a hand wrench designed to clamp onto the flats of a specific size nut or bolt head. The Wrench 10 is formed of flat stock with one end of the wrench frame I] terminating in a fixed jaw 14. An adjustable jaw I6 is pivot-ably mounted to the wrench frame 11 by a pin 17.

An operating lever arm 19 is pivotably mounted to the frame II by a pin 3l, with a link pivotably mounted to the lever arm by pin 32 and to adjustable jaw I6 by pin 33.

Rotation of lever arm 19 serves to move jaw I6 towards or away from fixed jaw 14, with continued rotation of pin 32 of lever arm 19 past the straight line joining pins 31, 32 and 33 serving to reverse the direction of rotation of jaw 16. When so rotated to the locked position shown in FIG. 1. the free end 20 of lever arm rests against a release arm 36 which rests against a fixed stop 37 pinned to wrench frame II.

In this position. the jaws l6 and I4 may be clamped about a bolt head between the jaws and the wrench frame ll rotated to rotate the clamped bolt or nut.

Release arm 36 is pivotably mounted to frame II by pin 23 and formed as an L shaped section with a grip end 22 protruding past the wrench frame 11 in the locked position of the jaws.

Rotation of release arm 36 against lever arm 19 serves to rotate jaw I6 past the dead center locked position so as to open jaw 16 as shown in FIG. 3.

A. hex-shaped opening I3 may be formed in the free end of frame I} to serve as a conventional closed wrench grip for a nut or bolt head.

Since obvious changes may be made in the specific embodiment of the invention described herein, such modifications being within the spirit and scope of the invention claimed. it is indicated that all matter contained herein is intended as illustrative and not as limit' ing in scope.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent of the United States is:

l. A wrench fitted with a fixed jaw and an adjustable jaw, said adjustable jaw pivotably joined to the frame of the wrench and to a link which serves to lock the adjustable jaw in one fixed position, with reference to the fixed jaw, said adjustable jaw being pinned to the said link, which link is pinned to a rotatable lever arm, with the rotatable lever arm pinned to the wrench frame so that rotation of the lever arm rotates the center of rotation of the link on the lever arm past a straight line joining the center of rotation of the said lever arm and the center of rotation of the said link pinned to the adjustable jaw, with a stop member mounted on the wrench frame which engages the lever arm to limit rotation in the locking direction of said lever arm after the lever arm has rotated the link pin past the straight line joining the center of rotation of the link pin on the adjust ablejaw with the center of rotation of the lever arm. in which a pivotable release lever is positioned between the layer arm and the fixed stop, said release lever being pinned to the wrench frame, said release lever formed with a projecting handle section that extends free of the lever arm and the wrench frame in the en gaged position of the release lever. the lever arm and the stop member, so that manual pressure may be exerted. in said engaged position, on the projecting handle section to rotate the release lever thus causing rotation of the lever arm away from the stop member in the unlocking direction.

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1. A wrench fitted with a fixed jaw and an adjustable jaw, said adjustable jaw pivotably joined to the frame of the wrench and to a link which serves to lock the adjustable jaw in one fixed position, with reference to the fixed jaw, said adjustable jaw being pinned to the said link, which link is pinned to a rotatable lever arm, with the rotatable lever arm pinned to the wrench frame so that rotation of the lever arm rotates the center of rotation of the link on the lever arm past a straight line joining the center of rotation of the said lever arm and the center of rotation of the said link pinned to the adjustable jaw, with a stop member mounted on the wrench frame which engages the lever arm to limit rotation in the locking direction of said lever arm after the lever arm has rotated the link pin past the straight line joining the center of rotation of the link pin on the adjustable jaw with the center of rotation of the lever arm, in which a pivotable release lever is positioned between the layer arm and the fixed stop, said release lever being pinned to the wrench frame, said release lever formed with a projecting handle section that extends free of the lever arm and the wrench frame in the engaged position of the release lever, the lever arm and the stop member, so that manual pressure may be exerted, in said engaged position, on the projecting handle section to rotate the release lever thus causing rotation of the lever arm away from the stop member in the unlocking direction. 